Referring now to FIG. 1, mobile air blower units are commonly used in the removal of grass clippings and leaves from lawns and other surfaces. Mobile blowers also are used to clean parking lot surfaces and to clean out cracks in paved surfaces prior to sealing the parking lot surface or filling the cracks. In addition, blowers are used to move rubbish and debris from sports stadia after a sporting or other event.
Typically, these blowers are powered by gasoline engines or elector motors (hereinafter referred to collectively as motors) which rotate a fan (not shown) in a housing 113 to generate a high velocity air stream which is directed at the leaves or debris. Frequently, as the blower is pushed near the vicinity of an automobile in a parking lot there is a risk that dirt, grit, small stones and other objects will be projected toward the vehicle and damage the paint or body of the vehicle. When a blower is used on a lawn or to blow leaves the same need to redirect the air stream may occur. As the blower approaches a vehicle in a driveway, or a flower bed, or other delicate object or structure it may be desirable to redirect the air stream to avoid blasting the object with the high velocity air stream. However, those familiar with mobile blower units will appreciate that seldom is a blower provided with a means of halting the operation of the fan, and the air stream, without turning off the motor.
Another problem with prior art blower units is the inability to redirect the entire air stream as the blower is moved along a path of travel. In one blower device provision is made for subdividing the air stream to direct a portion of the air stream upwardly and a portion of the air stream downwardly. Such manual air stream splitting and redirection can be seen in U.S. Pat. No. 5,735,018 to Gallagher et al, however, the Gallagher device does not permit the operator to redirect the entire airstream or to continually move or redirect the air stream as the device is moved by the operator along a path of travel.
The device of Gallagher relies upon a deflector (48) which is mounted within the discharge chute (24) of the blower (10). The deflector can be positioned to deflect a portion of the air stream upwardly or downwardly depending upon the operator's selection of the angle of the deflector. The device of Gallagher embodies the drawbacks that the air stream leaving the blower becomes subdivided and, therefore, the full force of the air stream is no longer brought to bear on the object to which it is directed. Gallagher also has the limitation that the operator is not able to move the deflector while pushing the machine. Rather, the operator must manipulate the deflector by hand into a new position. Further, for safety reasons, the operator should shut down the Gallagher blower before changing the direction of the deflector.
Referring again to FIG. 1, an alternative prior art blower is shown having a discharge chute 102 which is provided with a top mounted deflector 104 and a diverter plate 106. Diverter plate 106 is utilized to divert or deflect the air stream from exiting laterally as shown in FIG. 2, and to redirect the air to exiting discharge chute 102 in a forward direction as shown in FIG. 3. It will be appreciated by those skilled in the art that the introduction of the diverter plate 106 into discharge chute 102 does not provide a smooth transition between the air flow directed laterally and the air flow being redirected to the forward direction. This deflection method causes disruption of laminar flow and tends to reduce the force of the air stream and to introduce turbulence into the air stream as the air exits discharge chute 102 in the forward direction as shown in FIG. 3. Therefore, it would be advantageous if a blower 101 was provided with a discharge chute that is capable of directing an air blast laterally and forwardly without the introduction of diverting devices which reduce the force of the air blast and which increase the amount of turbulence in the air stream which further reduces the force of the air blast exiting discharge chute 102.
It would be a further advantage if a blower device 101 were provided with a means for allowing the operator to redirect the air stream up and down as the blower is pushed along a direction of travel. The ability to move the air stream up and down can be a particularly useful attribute depending on the type of leaves or debris being moved. In the case of wet leaves it is useful to be able to direct the air stream downwardly at the ground and at a sharp or acute angle in order to direct a strong air blast at the wet leaves or debris. However, once the leaves have been loosened, or when leaves are dry the air blast can be directed higher so the dry leaves are blown farther during the pass of the blower unit. Therefore, it also would be useful to be able to oscillate the air stream up and down to be able to loosen wet leaves and debris while being able to rapidly raise the level of the air stream to redirect the air force and blow the loosened debris farther away from the blower in one pass.
A further limitation of present blowers is that the air stream is generally directed lateral to the direction of travel of the blower. That is, the blower is pushed in a forward or rearward direction and the air stream is directed to the side. While this sideways direction of the air stream is useful in sweeping large surface areas, it is not useful when the task involves a small, long area such as the cleaning out of a crack in pavement prior to sealing the crack. Prior art devices generally require that the blower be pushed and pulled back-and-forth along the crack so that the laterally discharged air stream can be directed into the crack in the pavement that is to be filled. This results in a very tedious operation and substantially slows down the process of cleaning out cracks in streets and parking lots so the cracks can be filled.
The present invention overcomes these problems and limitations of the prior art devices by providing an air stream director which allows the blower operator to provide oscillating, up-and-down, movements of the air stream while also pushing the blower along a path of travel. The present invention also provides the blower with a neutral positioning of the air stream which can be used by the operator when the blower is proximate to an object or surface which might be damaged. The present invention can also provide the operator with a "deadman switch" for the repositioning of the air stream so the air stream is immediately directed to a neutral position which avoids the blowing of debris when the operator is not able to give attention to the blower as it is moved. In addition, the present invention overcomes the required back-and-forth movements of previous blowers by allowing the air stream to be redirected to the frontward or rearward directions and, if desired, to be oscillated up and down to allow more efficient cleaning of long thin areas such a cracks in pavement.